Process and apparatus for the regulation of steam boilers



J. LOUMIET ET LAVIGNE PRO S AND APPARATUS FOR THE.

Dec. 15, 1953 CES REGULATION OF STEAM BOILERS 9 Sheets-Sheet 1 Filed June 24, 1943 k m t llrllallll I INVENTOR.

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Dec- 15, 1 J. LOUMIET ET LAVIGNE 2,652,507 1 PROCESS AND APPARATUS FOR THE REGULATION OF s TEAM BOILERS 9 Sheets-Sheet 3 Filed June 24, 1943 JNVENTOR. J54 Jay WE? I D 1 J. LOUMIET ET LAVIGNE 2,662,507

PROCESS AND APPARATUS FOR THE REGULATION OF STEAM BOILERS Filed June 24, 1943 9 Sheets-Sheet 4 D 15, 1953 J. LOUMIET ET LAVIGNE 2,662,507

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M L M 1 M r E ,Z W 5 M J. LOUMIET ET LAVIGNE 2,662,507 PROCESS AND APPARATUS FOR THE Dec. 15, 1953 REGULATION OF STEAM BOILERS 9 Sheets-Sheet 7 Filed June 24, 1943 Dec. 15, 1953 J. LOUMIET ET LAVIGNE 2,662,507 PROCESS AND APPARATUS FOR THE.

REGULATION OF STEAM BOILERS Filed June 24, 1943 9 Sheets-Sheet 9 Patented Dec. 15, 1953 ht'bhdii? UNITED STATES PATENT HCE PROCESS AND APPARATUS FOR THE REGU- LATION OF STEAM BOILERS Jean Loumiet et Lavigne, Itabo, Cuba Application June 24, 1943, Serial No. 492,036 29 Claims. (01. 122-448) invention, all of the feedings pertaining to the a single drive which is controlled at all times to regulate the original water rate or the combustion feed rate according to the varying needs of the boiler. One or some of the original rates which have not been taken as a basis of original regulation constitute approximations of its or their definitive rates, and are rectified by means of a second regulation applied only to said rates, so as to adapt the proportion of their amount in relation with the amount of one or some of the rates constituting the basis of the original regulation according to the variable efficiency of the generator. When, for example, the original Water rate constitutes the definitive rate, the first regulation is effected preferably by virtue of the level of the water reserve in the boiler, so as to maintain that level at a predetermined height. The secondary regulation that rectifies at all times the original rates of means of combustion so as to adapt them to the efiiciency of the boiler is effected at the same time by virtue of the steam pressure so as to maintain said pressure constant. These methods of regulation are applied in accordance with the present invention to steam boil rs of the drumless forced flow type. In boilers of this type it is not only necessary to maintain a steam production constantly equal to the consumption, so that the pressure is maintained constant, and at the same time maintain the desired level of the reserve water, but it is also necessary to maintain the temperature of the superheated steam constant.

Steam boilers of the drumless forced flow type generally comprise three or four different units; the first unit is the vaporizer or saturated steam producer; the second unit is the superheater serving to superheat the ste" m produced in the vaporizer; the third unit is the economizer which operates to preheat the water before it is ejected into the vaporizer; and the fourth unit is a preheater of the combustion air.

If, for example, the steam load should be decreased by 50:'%, the heat transmission that must be effected in the vaporizer to produce the reduced amount of steam must also diminish by approximately "50%. However, the heat transmission surface of the vaporizer does not vary nor does the temperature of the water change. Therefore, in order that the heat transmitted heat, it is necessary for the temperature of the combustion gases to be reduced considerably, so of these gases is materially diminished, since their initial temperature does not vary. If this condition is maintained, the combustion gases would be cold when they emerge from the vaporizer, and therefore would not be able to raise the temperature of the steam in the superheater to the desired extent.

This problem which appears in the forced flow type of steam boiler is solved in accordance with the present invention by changing the amount of heat applied to the superheater, so as to adapt it at all times to the requirements of this part of the boiler. This result is obtained by deflecting or deviating a part of the combustion gases normally used for the heating of the vaporizer directly towards the superheater.

This deflection or deviation may be effected either near the inlet of the vaporizer or preferably beyond the inlet when the combustion gases have begun to cool. The combustion gases defiected have begun to cool. The combustion gases deflected in this way may be mixed with all or part of the normal heating combustion gases in the superheater. When the deflected gases are r not hot enough to cause destruction of the superheater tubes, they are preferably applied separately to the heating of said tubes until these gases have been cooled approximately to the temperature of the normal combustion gases in the superheater.

The method of heating the superheater as described may be applied to the economizer by diverting a predetermined proportion of the heat for its operation. The heat diverted to the economizer may be partly from the vaporizer or partly from the superheater, or may be from both of these units.

Also, the heating is employed.

By means of the diversion of the heating gases as described, distribution of a predetermined proportion of the heat produced by the combustion to each of the four units of the boiler will be maintained. The method of the present invention applied wholly in that way maintains constant the aliquot part of the total heat supplied by the combustion.

In spite of the advantage referred to, in practice a deflection of the heating gases sufficient to maintain constant the proportion of the combustion heat intended for the economizer and the air preheater respectively, can be frequently avoided. As a matter of fact, if by virtue of a diminution in the production of heat in the boiler, the normal heating gases of the economizer get cold, and cannot preheat the water therein to the normal operating temperature, the inlet portion of the vaporizer will have to do the necessary preheating of the water, so that the function of the first part of the vaporizer in heating to vaporizing temperature will be adversely affected. The evaporating part of the vaporizer will thereby act less effectively, since the heating of that part will be affected by the combustion gases that have been previously slightly cooled by virtue of the super-heating they have produced in the first part of the vaporizer. Both conditions of diminution of the heating surfaces and diminution of the temperature of the heating gas on its entrance causes an increase in the temperature of the gases at the outlet of the vaporizer, thus creating slight automatic compensation for the irregularity in the temperature produced in the heating gases by variation in steam consumption.

The reduction in a result of the reduction of the amount of the preheating of the air as boiler heat produced causes reduction in the temperature of the gases at their entrance in the vaporizer so that irregularities in the temperature produced in the gases by a variation in the steam consumption are slightly compensated for automatically.

Another problem presented in the application of the principles of the present invention to boilers of the drumless forced flow type results from the absence of a water reserve in these boilers. serve, the variable level of that reserve may constitute a control factor, since the volume variation of that reserve is a measure of the fluctuation of the water feeding. In accordance with the present invention, however, the regulation of the forced flow boiler is effected by employing as a control factor the water level variations of a separator disposed between the vaporizer and the superheater to extract from the steam produced in the vaporizer the liquid water it contains before discharging the steam into the superheater. However, the level of the water in the separator is not a true indication of the conditions of water feeding, because it depends both on the amount of water separated in the separator and the amount of separated water discharged from the separator.

According to the present invention, the separated water is discharged from the separator constantly and at a rate which is a predetermined proportion of the rate of the feeding of the water to the boiler, and represents the portion of the feeding water which it is desired to be contained in liquid state in the steam produced by the vaporizer when leaving the vaporizer. As a result of this proportional discharge of the separated water, the increase or reduction of the water in the separator is a true indication of the excess or deficiency in water feeding. The separator is provided above the normal level of the water with In the case of a boiler having a water rea discharge to compensate for cases where the feeding is excessive, and the control operates too slowly to correct this condition.

Various other objects, features and advantages of the invention will be apparent from the following particular description, and from an inspection of the accompanying drawings, in which:

Fig. 1 is a diagrammatic view showing the general application of the principles of the present invention;

Fig. 2 is a view partly in side elevation and partly in vertical section of a unit by which control is effected in accordance with the present invention in response to variations in the water level in the separator;

Fig. 3 is a view partly in side elevation and partly in vertical section of a unit by which control is effected in accordance with the present invention in response to variations in steam pressure;

Fig. i is a vertical section of a boiler in which the gases of combustion are distributed to the various units thereof in accordance with the present invention;

Figs. 4A, 4B and 4C are fragmentary views of different parts of the boiler shown in Fig. 4.

Fig. 5 is a diagrammatic view showing another general way in which control of a boiler may be effected in accordance with the present invention;

Fig. 6 is a view partly in side elevation and partly in vertical section showing a control mechanism applied to a boiler having a substantial reserve of water; and

Fig. 7 is a diagrammatic view showing another general way in which control of a boiler may be effected in accordance with the present invention.

Referring to Fig. 1 of the drawings, there is shown a steam boiler of the drumless forced flow type having a burner Q, and having heating surfaces, the first part of which is a vaporizer V, the second part a superheater R, the third part an economizer E, and a final part a combustion air preheater CA. A part of the combustion gases that normally would be employed to heat the vaporizer V along its full length is deflected through a passage P for discharge into the superheater R. This deflection is controlled by a valve C, which in turn is governed by a mechanism in driven by an electrical pyrometer Te according to the steam temperature so as to maintain this temperature constant. A second portion of the combustion gases from the vaporizer V is deflected by means of the duct P, and discharged directly into the economizer E. The rate of defiection of the combustion gases through the duct 1? is regulated by a valve C, which is governed by the mechanism ml, which in turn is operated by the electrical pyrometer Te according to the temperature of the outlet water in the economizer E, so as to maintain that temperature constant.

The various feeding mechanisms for the boiler are driven in unison from a single drive motor shown in the form of a turbine T. The water feeding pump BW, the water extracting pump BR for the separator H, the fuel oil pump BP for the burner Q, and the combustion air blower VA are driven from the turbine T through a suitable speed reducer RT. The water discharge pump BR has its discharge side connected by the pipe Re to a tank TW that supplies the feed water to the pump SW. The oil pump BD discharges the fuel oil to the burner Q through the pipe Pe, and the blower VA discharges air to the trolled by virtue of the steam pressure in the broiler, through the manometer M and the mechanism Mr, which in turn govern the movement of a motor Z which actuates a steam valve 1) at the inlet of the turbine T.

According to the process and construction of Fig. 1, the original rates of means of combustion are set at a predetermined value, while the original rate of water feeding is changed to adapt it in relationship with the rates of means of combustion to the variable efficiency of the motor. For that purpose, a valve w permits the return to the tank TW of a part of the pumped water, and the control of this return is effected in response to the variation in the water level in the separator H. This variation in the level of the water in the separator H causes a variation in the level of the gauge N to operate the regulator N1", the electric current of which operates the motor Z actuating the valve 20. To provide for any excess of water in the steam, a discharge D is connected to an elevated portion of the separator H, and connects into a trap Tr, the outlet side of which connects with the tank TV], so that any excess of water accumulated in the separator H is discharged through this pipe D into the tank TW.

The boiler in Fig. 1 operates as follows: The water pumped from the tank TW by the pump BW is delivered along the tube W to the economizer E. During this delivery, the excess of the water pumped is by-passed from the original rate of feed by the valve to controlled by the water level variations of the separator E. This bypassed feed water is returned to the inlet side of the pump BW. The feed water delivery through the pipe W passes through the economizer E,

through the pipe We and into the inlet side of the vaporizer V. In this vaporizer V, the water is changed into steam which is almost saturated except for a small proportion of liquid Water,

separated by the centrifugal coil S in the upper section of the separator E. This coil S is helicoidal in shape, and as the steam flows therethrough at high speed, the liquid water is forced radially outwardly from the coil by centrifugal action and is collected as water in the separator H. This separated water is discharged from the separator H constantly by the pump BR at a rate which is a fixed proportion of the rate of feeding of the water into the boiler, so that the water level variations in the separator H are a true measure of the diiference of the amount of non vaporized water contained in the saturated steam in relation to the water returned through the tube Re and pump BR to the feed tank TW.

The saturated steam is discharged from the coil S into the unit R- Where it is superheated, and the resulting superheated steam is discharged from said unit for whatever industrial use is desired.

The combustion gases resulting from the operation of the burner Q successively heat the vaporizer V, superheater R, economizer E and air preheater CA. A portion of these heating gases is deflected through the duct P into the superheater R to supply enough heat thereto to superheat the steam to the desired temperature. Another portion of this heating gas is deflected through the duct P directly to the economizer E to supply to it the necessary heat to preheat the feed water to the desired temperature before it enters the vaporizer V.

Fig. 5 shows the same general arrangement as that shown in Fig. 1, except that the feeding rates of the combustion elements are controlled instead of the rate of water feeding. This control of the rates of feeding of the combustion elements has for its object to adapt the proportions of the feeding of these elements in relation with the Water feeding to the efiiciency of the boiler which varies according to stem. consumption. This object may be obtained either by control of the original rate of water feeding, as in the construction of Fig. 1, or by regulation of the rate of feeding of the combustion elements, as in the construction of Fig. 5.

In Fig. 5, the regulation of the feed or" the combustion elements is effected by two different control factors. The first control factor is the amount of steam production of the boiler. When other operative conditions do not vary, the efficiency of the boiler depends on its steam production. Therefore, the correction that must be effected Whether in the original rate of water feeding or in the original rates of feeding of the combustion elements for adapting the proportion of the feedings to the efiiciency of the boiler is substantially the same when the steam production of the boiler is reestablished at the same value. Therefore, that correction may be applied to the regulator Mr as a means for governing such corrections in the same form that governs the speed of the turbine T producing the movement by which the original feeding rates are obtained.

Control in the original rate of feeding of fuel oil is effected by the mechanism m'p, and control in the original rate of feeding of the combustion air may be effected by the mechanism ma. These mechanisms can be operated alone, but in order to provide for variable conditions such as those resulting from moisture in the air or the extent of cleanliness of the boiler tubes, etc., the control of the mechanism 'm'p and ma is advantageously complemented with another control effected in accordance with the Water level in the boiler, so as maintain that level constant. This second or supplementary regulation or control is effected in the oil feed by the mechanism mp, and in the combustion air feed by the mechanism ma. In the construction of Fig. 5, the regulation of the rates of feed of the combustion elements is effected through the two control factors above pointed out operated simultaneously. In the construction of Fig. l, the regulations that eifect the adaptation of the proportions of the original feeding rates to the efficiency of the boiler by means of the correction of the original rate of water feeding may be effected by the same two control factors, i. e., by the mechanism operated in accordance with the pressure variations in the boiler that govern the operation of all of the feeding mechanisms and also by the water level in the boiler.

In both of the constructions of Figs. 1 and 5, the first regulation resulting from a change in steam consumption changes the rate of feeding of all of the feeding mechanisms to the same proportional extent to correspond to that change in consumption, while the second or supplementary regulation that rectifies the first regulation is governed by the deficiencies observed in practice, so that these deficiencies are corrected.

Referring to Fig. 5, the deflections of the combustion gases in the ducts P and P are also partially governed by the mechanism Mr, so as to automatically obtain in the regulation effected by that mech nism, opening of those ducts corresponding to the amount of feedings at that moment, which feedings correspond in the long run to the steam production. Theoretically, the amount of opening of the valves C and C1 corresponds to the steam production, so that the regulation effected by the mechanism MT must automatically apply to the opening of both valves a first regulation very close to the required regulation. This regulation alone can be established, but bearing in mind the variable factors, such as the moisture in the combustion air and the degree of cleanliness of the boiler tubes, it is desirably accompanied by a second regulation that operates in conjunction with it or separately of it, and which is governed according'to the specific deficiency observed in the obtained results, that is for the respective variations in the temperature of the produced steam and of the water feed at the entrance to the vaporizer V. In accordance with the construction of Fig. 5, the con trol effected by the mechanism Mr is performed by the mechanism m for the valve C, and by the mechanism me for the valve C1.

The control of the valve C is governed by a thermostat Te operated in accordance with the variations in the temperature of the steam produced at the outlet of the superheater, and is effected by the mechanism m and the control of the valve C1 is governed by the thermostat Te operated by the water feed at the outlet of the economizer E, and is effected by the mechanism mi.

The superheater R is divided into two parts by the wall I. The part of the superheater R to the right of this wall I is continuously heated by the normal combustion gases, while the part to the left of said wall is heated by the combustion gases deflected through the duct P and also with a certain amount of normal combustion gases. This permits the combustion gases deflected through the duct P to be maintained at a temperature higher than that of the normal gases, thereby increasing the heat transmission in the outlet section of the superheater. The same wall arrangement J may be applied for the heating of the economizer E.

In Fig. 7, the control for the motor (steam pressure) effects supplementary control of the water feed. To that end, a valve w is provided permitting return to the tank TW of a part of the pumped water, as in the construction of Fig. 1 and the control of this return is effected in response to the boiler pressure by means of a mechanism Mw operated from the regulator Mr. To provide for variable conditions, the control of the mechanism Mw is complemented with another control, operated in accordance with the water level in the separator H. This second or supplementary regulation or control of the water feed return valve 10 is efiected by means of a mechanism Nw operated from the regulator Nr. In all other respects, the system of Fig. '7 is similar to that illustrated in Figs. 1 and 5.

Referring to Fig. 4, there is shown an application of certain features of the invention to the control of the combustion gases in their distribution to the vaporizer, superheater, economizer and air preheater of the boiler to maintain constant the proportions of the total heat diverted to each of these units. In this construction, there is provided the vaporizer V, superheater R, economizer E and air preheater Ca. A portion of the combustion gases flowing through the vaporizer V is diverted by means of the passage P passing below the wall F, and. having branch conduits Pr leading to the supreheater R, conduits Pe leading to the economizer E, and conduit Pc leading to the air preheater Ca. The superheater R, is divided into four sections independently of each other with respect to the heating thereof by the thin walls 11, I2, and Is. The entrance of the normal combustion gases that come from the vaporizer V, as well as the entrance of the combustion gases that come from the conduit Pr, are governed in each one of these superheater sections respectively by the valve C1, C2, C3 and C4 so controlled and regulated as to vary the flow of normal combustion gases through the normal inlet of any one of these valves while simultaneously diminishing the flow of deflected combustion gases through the deflection inlet of the same valve and vice versa. Also, the valves C1, C2, C3 and C4 are operated in sequence. This progressive regulation, elfected by means of the motor mR causes a rack Rd to move vertically from top to bottom. This rack Ra is long and has a set of teeth Rb on one side meshing with a motordriven pinion Re by which said rack may be moved up and down and has a set of teeth Rd on the other side extending only along a short portion of said rack for engagement with the pinions R of the valves C1, C2, C3 and C4.

The wall of the superheater R has sectorshaped openings Cbl, C112, C173 and CD4, one for each superheater section, establishing communication between the gas diverting conduit Pr and the corresponding superheater section, and the partition walls I1, I2 and Is of these superheater sections define with each other and with the vaporizer Walls, openings Cdr, Cdz, Cds and Cd; establishing direct communication between the upper end of the vaporizer V and the inlet ends of the superheater sections respectively.

For controlling the openings leading into the superheater sections from the gas diverting conduit Pr and from the upper end of the vaporizer V, each of the valves C1, C2, C3 and C4 comprises a shaft Ce carrying the pinion Rf adapted to mesh with the rack teeth Rd and having two plates C1 and Cg at right angles to each other rigid with said shaft Ce. The plate Cf extends across the inlet of the corresponding openings Cd1, Cdz, Cds and C114 to serve as a damper to control the extent of said opening and the other plate Cg which is sector-shaped and slightly larger than the corresponding opening Cbl, Cbz, Cb: or C124, extends across the latter opening and serves as a slide valve therefor.

When the rack Ra is in the intermediate position shown, the valves C3 and C4 will be wholly closed as shown against passage of the deflected combustion gases that come from the conduit Pr into the two lower sections of the superheater, while opening these sections to the passage of the normal combustion gases from the vaporizer V. When the rack Ra is lowered from its uppermost position in which uppermost position the valves 01 and C2 are reversed from the positions shown in Figs. 4 and 4A, the teeth Rd of said rack first drives the pinion R) of the valve C1, causing said valve to open the entrance of the upper superheater section to the passage of the combustion gases deflected by the conduit Pr, while closing the entrance to the passage of the normal combustion gases. The overall length of the racl: teeth Rd is such that when said rack teeth finish their mesh with th pinion Rf of the valve C1, that valve totally closes sage of the normal gases from the vaporizer V to the superheater section opening Cch. At this stage, the lower part of the rack teeth Rd is almost in mesh with the pinion of the valve C2. In this way, as the control is operated to increase the amount of the deflected combustion gases applied to the superheater resulting from the lowering of the rack, the number of opened valves is progressively increased from top to bottom. The reverse operation is effected when the rack is lifted.

Every one of the valves C1, C2, C3 and C4 is constructed so that it rests by its own weight in a stable position in each of its extreme open and closed positions.

The combustion gases deflected towards the economizer E by the conduit Fe are controlled at the entrance to said economizer by the valve (2'. These deflected combustion gases operate in the economizer E in the manner similar to that described in connection with the construction of Fig. 5, and for that purpose this economizer has a partition wall J dividing the economic 1" into sections Ea and Eb.

The upper end of the economizer E communicates with the outlet end of the superheater and the valve (2 comprises two valve members dc and (lb connected to a single shaft driven by a motor 'mE through a gear reduction. The valve member dc extends across the bottom of the economizer section Ea to control how of combustion gases from the superheater R through. said economizer section Ed and the valve member db extends across the outlet of the deflecting conduit P6 to control the flow of gases deflected from the vaporizer V into said economizer section Ed. The two valve members a e and db are arranged so that as one valve member moves into closing position to block off passage of one gas current (natural or deflected) into the economizer E, the other valve member opens up to permit the passage of the other gas current into said economizer.

Also, the combustion gases deflected towards the air preheater Ca by the conduit P0 are controlled by the valve 6 which is operated as a damper through a motor m0.

Fig. 2 shows a control device which can be operated in accordance with the level of the water in the separator H. Certain principles of this control device can also be employed to operate by virtue of the steam pressure variations in the boiler.

The control in accordance with the construction of Fig. 2 is eiiected by an electric motor drive which operates upon a corresponding valve in a desired direction to meet existing deficiencies. The control, therefore, is operated to supply the proper electric current to the motor to cause movement of said motor in the desired direc tion. In the construction of Fig. 2, there is provided a gauge N connected to the lower section of the separator H, and comprising bent tubes U and Rs containing a mercury column. The tube Rs is inclined to increase the sensitiveness of the the entrance to the pasmercury column, and has a small diameter, so that the upper part of the mercury column therein is in spherical meniscus form. The upper part of the tube Rs above the mercury column is full of condensed water, the level of which'is maintained fixed by means of an inclined extension Y connected at its lower end to the inclined tube Rs, and connected at its upper end to an enlarged chamber 211 of substantially large diameter than the tube Y. This chamber Za communicates with the interior of the separator H, and serves to collect steam condensations caused by cooling of tube Q0. The condensation in the chamber Z0; maintains a therein, and this chamber is any variations in the level of the mercury column in the tube Rs do not affect appreciably the level of the water in said chamber.

The tube Rs is metallic, and is of relatively small electric conductivity. Variations in the level of the water in the separator H causes a corresponding variation in the level of the mercury in the tube Rs, and this in turn causes a variation in the electric resistance of said tube. The control electric current is connected to one end of the tube R3 at b, and passes out from the other end of the tube at a. This tube end or terminal a is connected by a conductor to the upper end or terminal At of a device At- Et- F Ct-B. Current passes through this device from the terminal At through a resistance r contained in a tube Ct, and goes out from the terminal B to the current line I.

When the water the mercury in the big enough so that that passes through the circuit 2- ba At-Bl increases so that the heat produced by the passage of that current through the resistance 1' also increases. The tube Ct enclosing the resistance r is internally insulated, and contains a fluid, such-as methyl chloride, which is susceptible of evaporation upon the heating of the resistance r through the passage of current therethrough. Normally this fluid occupies in liquid state the lower part of the tube Ct where the resistance r is located, while the upper part of said tube contains the vapors of this fluid. The upper part of this tube Ct is connected with the upper part of a coil Et, the lower end of said coil being also connected with said tube Ct at its lower part near the end of the resistance r. This coil Et is enclosed in a housing F which receives cooling water delivered into said housing through an inlet W0, and discharged from said housing by an outlet The circulation of cooling water through the housing F condenses the methyl chloride evaporated as a result of the heat of the resistance r. The greater the current that passes through the resistance r, the greater will be the steam production in the boiler, and the greater Will be the difierence in temperatures required for the methyl chloride vapors to be condensed by the circulating cooling Water around the coil Et. The increase in temperature of the evaporated fiuid causes an increase in the pressure of this fluid. It is seen, therefore, that for any height in water level in the separator H, there is a corresponding predetermined pressure in the tube Ct. The device At-EtF-CtB, therefore, serves to translate variations in water level in the separator I-I into variations in the pressure in the tube Ct. The differences in pressure are materially greater than those of the level of the mercury in the tube Rs, and even constant liquid level 11 greater than those of the water level in the separator H, so that the device AtB not only serves as a means of translating level variations into pressure variations, but also serves to amplify these variations.

In the operation of the arrangement shown in Fig. 2, the pressure in the tube Ct is transmitted through a chamber G and a tube 10 full of oil or water, and this liquid in turn acts upon a mercury column in a U-tube Ja, Ma. This U-tube J a, Ma has branches L and parallel to the two main branches Ja and Ma of the U-tube. The two main branches Ja and Ma of the U-tube are interconnected by a loop K. The two branches Ja and Ma normally are full of mercury up to the entrance to the chambers or boxes Xa and Xb. These chambers Xa and Xb are full of a liquid which constitutes a bad conductor of electricity, such as kerosene or distilled water. Therefore, when the pressure rises in the chamber G, the mercury column in the branch J goes up, and the mercury column in the branch M goes down. This movement of the mercury column is resisted by the counterpressure resulting from the liquid in the main right-hand branch Ma. That main branch Ma has an extension Ta filled With water or other liquids to afford a substantial counterpressure to the movement of the mercury column in the direction indicated resulting from the increase in pressure in the chamber G. Instead of using liquid in the column Ta as a counterpressure medium, compressed air may be employed.

When the pressure is increased in the chamber G, the resulting upward movement of the mercury column in the branch J will cause it to come in contact with an electrode or terminal Pb, causing a passage of electric current through the circuit 22-Pbh-Sb-l. If this increase in pressure in the chamber G continues, the mercury discharges in the lower part of the box Xb, and by means of the check Q, flows into the tube 0, causing a rise in the level of the mercury in the right-hand tube branch Ma, maintaining thereby contact with the electrode Pb and the passage of current through the circuit 2--2'-Pb-h--Sb-l.

When the pressure in the chamber G is reduced, the mercury in the tube branch M goes up and tends to discharge in the box Xa. As a result of this movement, the mercury comes in contact with the electrode Pa, and current is thereby established in the circuit 2-2'--Pa--k-- Sa-I. As the pressure continues to fall in the chamber G, the mercury in the branch tube M discharges into the box Xa, and passes to the tube L through the check Q, and therefore causes the mercury column in the left-hand tube branch Ja to rise.

It must be understood that the amount of light liquids in the upper section of the loop of the tube K and the positions of the electrodes Pb and Pa are such that both electrodes will not be in contact with the mercury at the same time.

The mercury in the tubes J at, Ma, K, which are made of metal, is always in electrical contact with the terminal 2, and in turn with the power line 2. The electrode Pa is insulated from the metallic tubes K, L and M, and is in contact with the power line I by means of the line is. The electrode Pb, which is also insulated from the tubes K, O and J, is in electrical contact with the power line I by means of the line it.

Therefore, when the pressure chamber G goes up in response to the rise in the water level of the separator H, the mercury coming into electrical contact with the electrode Pb establishes electrical communication through the solenoid Sb. This causes the switch Ib to be closed, so that electric current flow is established through the circuit 2-Ib-2b, thereby delivering current to the motor to cause it to rotate in a direction to progressively close the water feeding valve.

When, on the other hand, pressure in the chamber G decreases, and the mercury rises into electrical contact with the electrode Pa, the solenoid Sa is energized to close the switch Ia, thereby closing the circuit of the line 2Ia-2a. This causes the motor to rotate in the opposite direction to cause progressive opening of the water feeding valve.

It is seen, therefore, that by means of the construction of the present invention, when the Water level in the separator H rises, the control device shown in Fig. 2 will operate to progressively close the water admission valve, and when the water level in the separator is reduced, this water admission valve will be progressively opened. The construction shown in Fig. 2 to produce this eifect may be modified in accordance with certain aspects of the present invention. For example, it is not necessary that the branch tubes J, M cross each other. The two main branches Jo and Ma may, for example, be connected by an inverted p open at the bottom.

Fig. 3 shows the application of the control device in response to the variation in the boiler pressure. In accordance with the construction of Fig. 3, the control in response to the variation in the water level'is effected by means of a tube system filled with different liquids and containing mercury operating in a capillary tube N slightly inclined with respect to the horizontal. The current that enters by means of the terminal a and leaves through the terminal 1), passes through the tube N. This tube N is of metal having low electric conductivity, and the resistance offered by this tube varies according to the level of the mercury therein. This mercury level in turn varies in accordance with the level of the water in the separator H. The control from this point is the same as that shown in Fig. 2.

In order to effect regulation in response to the variations in steam boiler pressure, there is provided a reservoir 0 containing compressed air, and a mercury tube in communication therewith and having an upper section T and a lower section J". The mercury column is under pressure resulting from the column M containing condensed water and an intermediate column 1" containing liquid of different density. If desired, this intermediate column I" can be eliminated, and the mercury made to extend into the tube G".

The amplifying device AtEtFCt-B of Fig. 2 has been eliminated in the construction of Fig. 3, since that device is desirable when the governing control factor is the water level in the separator H, which water level may vary by a small amount, but is not required when the control is effected automatically as a result of variations in the pressure in the high pressure boiler. For that reason, the two mercury columns in the manometer shown in Fig. 3, i. e., the upper column T and the lower column J operate in a similar manner as the columns of tubes Ja and Ma in Fig. 2. The U-tube K in the construction of Fig. 2 is replaced in Fig. 3 by the two branches Kb and Ka respectively communicating with the boxes Xb and Xa. The branches Kb and Ka, as well as the two boxes Xb and Xa are wholly full of a liquid which is a bad conductor of electricity, such as kerosene or distilled water. The upper mercury column T communicates freely with the box Xb, and is separated from the box Xa by means of a valve Qa, while the lower column J communicates freely with the box Xa, and is separated from the box Xb by a valve Qb. The boxes Kit and Xb with their electrodes Pa and Pb operate in a manner already described in connection with the construction of Fig. 2.

The circuit formed by the line 2, closed switches Ia and Ia, and the line 2a operate the motor to reduce the feed of the combustion elements. In order to close this circuit, it is necessary not only to close the switch Io, but also the switch I'a. This second condition represents in practice the demand that the range of the boiler pressure must be greater determined pressure taken as a basis. The basis pressure is the one controlled by the mercury column of the manometer as described, and its limits are determined by the terminals Vb and Va. When the pressure rises above this basis pressure, the mercury comes in contact with the terminal Va,'and this in turn closes the circuit 2-2-VaSd-i. The closing of the circuit through the solenoid Sci energizes this solenoid and causes closing of the switch Ia. Therefore, in order that the control operates in the man ner to decrease the boiler pressure, it is necessary not only that the pressure be rising, but that it be too high and reach a predetermined value. In the same way, in order that the circuit 2Ib-I'b-2b be closed to cause movement of the motor in the desired direction to change the feedings and thereby increase the boiler pressure, it is necessary not only that the mercury in the upper column T comes in contact with the electrode Pb in response to a fall in boiler pressure, and thereby closes the switch lb, but it is also necessary that the mercury is moved out of contact with the terminal Vb, indicating that the boiler pressure has dropped below the basis pressure causing the closing of the switch I'b.

The construction of Fig. 3 is shown for the situation when very small variation in pressure is required. Very often it is convenient to in crease the margin of boiler pressure variations so that the control operates only when the pressure varies beyond the limits of this margin. If we assume, for example, that the boiler is feeding a steam power machine, the amount of steam utilized by this machine is not cont nu ously constant, because of the stroke operation of the machine. It is therefore desirable in such a situation that the control does not operate directly in accordance with variations caused by the variations in steam consumption, but is regulated when the pressure goes beyond the margins of variations. The desired margins of pressure variations allowable by the control are obtained by spacing electrodes Va and Vb the desired extent. The spacing between these terminals or electrodes represents the margin of pressure variation which allowable without putting into operation the control device.

Fig. 8 shows the application of a control device to a steam boiler having a substantial re serve of water.

The problem of regulating steam boilers having a substantial reserve space for water is different than that present in the control of boilers than that of a a of the drumless forced flow type, which do not have any water reserve space. In this latter type of boiler, the control of the feed water must be efifected in such a manner as to correspond exactly to the rates of feed of the combustion elements, so that the amount of heat combustion available in the vaporizer exactly corresponds to the amount of heat required by the injected water for its vaporization, except for the margin of liquid water that is required to be contained in the steam leaving the vaporizer.

On the other hand, in boilers having a substantial reserve space for the feed water, the problem is very dinerent, because if it is true that in this case it is generally desirable also to balance the steam production with the steam consumption, when by virtue of former deficiencies in their equilibrium the water reserves that equilibrium have been materially altered in relation to their normal amount, and at the same time there exists an unbalanced condition between steam consumption and steam production which tends to reestablish the normality of the water reserves, that unbalanced condition must be kept in order to normalize the unbalanced water reserves of the boiler, and must not be increased, because by itself it represents the deficiency of operation that must be met when the water reserves have returned to normal conditions. In other words, while in the forced flow type of boiler the control effected in response to the water level in the separator must as soon as the variations in that level show an excess or deficiency in the water feeding in relation to the feedin of the combustion elements, in a boiler having a substantial reserve space for the water, it is not enough for the control to operate in response to an unbalanced condition between the water feeding the sealing of the combustion elements, but it is also necessary that the unbalanced condition does not operate favorably, i. e., that it does not correct existing deficiencies of the boiler water reserve. For that purpose, the construction of Fig. 6 comprises two electrodes Va and Vb which operate in a manner similar to the electrodes Va and Vb in the construction of 3, to restrict the operation or" the control intended to correct an unbalanced condition resulting from the variations in the boiler water reserves. The movement of the mercury column in the tubes M and is effected in response to the pressure in the chamber G, which pressure depends on the height of the water in the boiler.

The electrodes Va and Vb are positioned to obtain contact with the mercury in the tube Ma. The electrode Vb is placed at such a height that the mercury comes in contact with it when the water in the boiler has reached an excessive level that requires regulation.

When that situation arises, the mercury in the branches J and Ma. rises to levels to establish mercury contact with the electrode Pb in said branch J and to establish mercury contact with the electrode Vb. At the same time, the mercury in the branch M is lowered out of contact with the electrode Pa. i'hese operations cause the circuit formed by the line 2-42, tube K and branch Ma, the mercury in said branch Ma, the electrode Vb, the solenoid Sci and the power line I to close, thereby energizing the solenoid Sci and causing the solenoid switch Ib to close. At the same time, the circuit is closed through line 22', the tube K and branch J,

the mercury in said branch J, the electrode Pb, the line h, the solenoid Sb and the power line 1, thus energizing the solenoid Sb and closing the solenoid switch lb. The closing of the two solenoid switches Ib and 1b causes closing of the circuit comprising the line 2, switch Ib, line 2b, switch lb, line 2b, the motor Z (Fig. 1) operating the feed water valve w to be controlled and the power line i, thereby effecting rotation of said motor in a direction to effect compensatory regulation of the excess of water feeding.

The electrode Va is in such a position that when the mercury dropping through the tube Ma loses contact with that electrode as a result of the water level in the boiler falling below a predetermined height, then the electric circuit through the line 2-2, tubes K and Ma, the mercury in tube Ma, electrode Va, solenoid Sc and power line i opens, so that the solenoid So is deenergised, thereby causing the solenoid ia to close. At the same time, the mercury level in the branch M rises to establish contact with the electrode Pa, causing thereby the circuit to close from line 2-2', through tube K and branch M, electrode Pa, line power line i. This energizes the solenoid Sa and causes it to close the switch 10.. The closing of the two switches Ia and la closes the circuit through line 2, switch Ia, line Z'a, switch I'd, the power line 2a, the motor Z (Fig. 1) controlling the feed water valve to and the power line I, thereby effecting rotation of said motor in a direction to effect c mpensatory regulation to meet the deficiency in water feeding.

In conclusion, the control system of the present 3 invention regulates at all times the feeding rates of water and the feeding of the combustion elements (fuel and air) according to the variable needs of the boiler. This control system serves (1) to limit the control factors to the water level in the separator and the steam pressure of the boiler; (2) to supply all of the feedings at original proportionally predetermined rates, and regulate that supply in accordance with one of the two control factors referred to, while the adjustments in the proportions of the original rates of feed of the combustion elements, or of the original rate of water feeding to adapt them to the variable efficiency of the boiler, is effected by the second control factor; (3) to apply the speed of movement that supplies the original rates, i. e., of the factor of regulation that governs that movement to the regulation of those changes to constitute a previous approximation of this second regulation; and (4) to effect regulation in such a way as to require in order to meet a deficiency that the variations of that deficiency do not show it is diminishing in that same moment.

The complete regulation of steam boilers of the drumless forced flow type, and generally of all boilers having steam superheaters, presents another problem. That regulation must not only provide for the feeding of water to compensate for the vapor consumption, but also must provide the necessary heat to effect operations of the boiler by means of suitable adjustments in the amounts of the feedings of the combustion elements. It is necessary that the heat be absorbed by the vaporizer, superheater, economizer and air preheater if they exist proportional to the needs of these parts if these must function properly. In order for the absorption of the heat to be effected properly in the required proportions in the different units, it is necessary to adapt the temperature of the combustion gases at the entrance to is, solenoid Se and each of these units to produce the required heat exchange between these gases and the fluid in these units. If that condition is not effected and the total heat received from the combustion is not absorbed in constant proportions by thefluid in the successive units of the generator, it would be impossible for these units to carry out their proper function efficiently.

In boilers which are not provided with a water separator at the outlet of the vaporizer, as for example, in the Benson type of boiler, the lack of regulation or control of the temperature of the combustion gases causes undesirable variation in the section of the tubes in which total vaporization of the water takes place.

The absence of that same regulation or control in boilers having a water separator or a drum at the outlet of the tubular vaporizer operating with an excess of water, causes differences in the degree of heating of the steam.

The present invention solves all the problems of regulation, and at the same time allows the injected water to exactly compensate for the steam used with a slight excess established at the operator's convenience to maintain moisture of the steam at the outlet of the vaporizer, and also causes the feeding of the combustion elements to correspond exactly to the thermal needs of the boiler, and to maintain at a predetermined value not only the pressure of the superheated steam, but also its temperature.

I have described what I believe to be the best embodiments of my invention. I do not wish, however, to be confined to the embodiments shown, but what I desire to cover by Letters Patent is set forth in the appended claims.

I claim:

1. A process for regulating the operation of a steam boiler of the drumless forced flow type having a vaporizer traversed by the water being operated on in a single pass, a superheater, a separator between the vaporizer and the superheater for the water contained in the steam only, and a single drive motor for operating all of the feeding mechanisms to the boiler including the boiler feed pump, which process comprises controlling said motor automatically in accordance with the pressure variations in the boiler, discharging from the separator and extracting from the system the separated water at a rate proportional to the water discharge rate from the outlet of the water feed pump and at a rate corresponding substantially to the amount of liquid water it is desired for the saturated steam to contain at the inlet of the separator, controlling the proportion between the amount of the feeding water and the amount of the feeding elements of combustion automatically in accordance with the increase or decrease of water in the separator, to adapt the operation of the feeding mechanisms to the variable efficiency of the boiler, deflecting directly towards the entrance of the superheater an adequate portion of the combustion heating gases from the vaporizer before they have traversed half of the heating surface of the vaporizer, and regulating automatically the proportion of the deflected gases in accordance with the temperature of the superheated steam in order to maintain said temperature constant, while the remaining portion of the combustion heating gases in the normal flow traverses the balance of the vaporizer heating surface before entering the superheater.

2. A process for regulating the operation of a steam boiler of the drumless forced flow type as described in claim .l',,in which an economizer is provided in said boiler, andin which a portion of the, combustion, gases normally flowing towards said economizer through the vaporizer a'e deflected from the main flow stream to by-pass an outlet section of said vaporizer and to direct the deflected portion of the gases towards said economizer, and in which the amount of combustion gases deflected to said economizer is controlled in accordance with the temperature of the Water at the outlet of said economizer to maintain said temperature constant.

3. A process for regulating the operation of a steam boiler or the drumless forced flow type as described in claim 1, comprising the steps of causing normal and deflected currents of heating gases from the vaporizer to pass over various successive sections of the superheater, controlling the proportion of heating gases in the currents in each of said superheater sections so that as greater amounts of deflected gases are required, the by-passes controlling the amount of deflected gases flowing into the superheater sections respectively are opened progressively and in consecutive order, while the openings controlling the now of the normal gases flowing into said superheater sections respectively are closed progressively and in consecutive order to a corresponding extent, whereby the deflection by-pass and the opening for normal gases leading to each of said supcrheater sections is operated in reverse rela tionship to open the one while closing the other, and whereby th flow control operation in the by-pass and opening for each superheater section is finished before the control operation in the by-pass and opening for normal gases for the next successive superheater section is initiated.

4. A process for regulating the operation of a steam boiler of the drumless forced flow type as described in claim 1, in which the means for feeding water, fuel and combustion air are operated in unison to supply said feed elements at predetermined proportional rates, and are controlled by the steam pressure of the boiler to maintain said pressure substantially constant, and in which the excess of fuel feed at the outlet of the fuel pump is returned to the inlet of said pump in accordance with the Water level variation in the separator.

5. A process for regulating the operation of a steam boiler of the drumless forced flow type as described in claim 1, in which the means for feeding water, fuel and combustion air are operated in. unison and? at'relative speeds to supply said feed elements at original rates proportioned to satisfythe needs of the boiler when it operates according to condition of substantially maximum efiiciency, and in which the original proportional rate of feed of the fuel feed is corrected in accordance with the water level variations in the separator to maintain the level of the water in said separator constant.

6. A process icrregulating the operation of a steam boiler of the drumless forced flow type as described in claim 1, in which the original feeds of the water and of the combustion elements comprising fuel and combustion air are supplied through the operation ofsaid single drive motor controlled by the steam pressure of the boiler to maintain said pressure constant, said process comprising the steps of supplying said feeds at original rates; proportioned to satisfy the needs of the boiler when the boiler operates according to the condition of: substantially maximum eiiirciency, applying the control for said motorto effect a supplemental control of the rate of the Water feed alone to obtain according to the chiciency theoretically corresponding to the existing speed of said motor, the first approximation in adjustment of the proportion of water feed rate in relation to the rate of feed of the combustion elements, and returning the excees of water feed from the outlet of the Water feed pump to the inlet of said water feed pump before injection into the boiler in response to the control operating in accordance with the Water level variations in the separator, to maintain the level of water in the separator constant.

7. A process for regulating the operation of a steam boiler of the drumless, forced flow type as described in claim 1, wherein the control for the motor is also applied to effect supplementary control of the rate of feed of the combustion elements to obtain the first approximation in adjustment of the proportion of the feed rate of the combustion elements to the rate of water feed to adapt this adjusted feed rate of combustion elements to the efiiciency of the boiler.

8. A. process for regulating the operation of a steam boiler of the drumless, forced fiow type'as described in claim 1, wherein the control for the motor is also applied to effect a first regulation of the amount of combustion gases deflected towards the superheater and to vary that amount inversely to the variations of the pressure to maintain the temperature of the superheated steam substantially constant.

9. A process for regulating the operation of a steam boiler of the drumless forced flow type as described in claim 1, wherein an economizer is employed, and a portion of the normally flowing combustion gases in the boiler is diverted to said economizer, and wherein the control for the motor is also applied to effect a first regulation of the combustion gases diverted to the economizer to vary its amount inversely to the variations of the pressure.

10. A process for regulating the operation of a steam boiler of the drumless forced fiow type as described in claim wherein the control responsive to boiler pressure operates only when said pressure goes beyond maximum and minimum limits, and only while said pressure is increasing its deviation from said limits.

11. A control apparatus for regulating a steam boiler of the drurnless, forced flow type having a separator by means of the water level variations in the separator of the boiler, comprising means for translating the Water level variations into pressure variations in a source of control pressure, an upright U-tube having intermediate. its main side arms an inverted U-shaped loop, and having its lower section filled with mercury and its upper section filled with a liquid of relatively low electrical conductivity, a box communicating with each arm of said loop, an upright tube extending from the base of said U-tube to its corresponding box, a valve preventing passage of the liquid from said upright tube to its corresponding box, means connecting one of the main arms of said U-tube With said source of control pressure, means connecting the other main arm of said U- tube with a source of fluid counterpressure, a pair of electrodes in said boxes respectively insulated from said boxes and positioned to contact with the mercury in the loop arms as said mercury tends to discharge in said boxes, a solenoid in the circuit ofeach electrode energized when the mercury contacts said latter electrode, a motor, a valveoperated by said motor, and means operable when either one of said solenoids is energized to drive said motor in appropriate direction to regulate said latter valve.

12. A control apparatus as described in claim 11 for regulating a steam boiler from said motorcontrolled valve, comprising an electrode posi tioned at one of the main side arms of the U-tube to a height suiiicient to come in contact with the upper level of the mercury when the operation of the boiler to be controlled begins to increase in excess of its normal condition, a solenoid operated when said latter electrode is contacted by said mercury in said latter side arm, and means for controlling the direction of said motor when said latter solenoid is energized to decrease the excess of said boiler operation.

13. A control apparatus as described in claim 11 for regulating a steam boiler from said motor= controlled valve, comprising an electrode positioned at one oi the main side arms of the U-tubc to a height sufficient to come in contact with the upper level of the mercury when the operation of the boiler to be controlled begins to fall below a predetermined value, a solenoid operated when said mercury reaches said latter electrode, and means for controlling the direction of said motor when said latter solenoid is energized to increase said boiler operation above said value.

14. An apparatus for translating water level variations in a boiler into pressure variations in the control of the boiler, comprising a. body partially full of a liquid that becomes easily volatile at low temperature, an electric resistance in the part of said. body containing the unvolatilized liquid connected to an electric circuit, means for translating water level variations in the boiler into current impulses through said electric resistance, and a condenser having a fixed heat transfer surface that receives the vapors from said body and returns them in condensed form.

15. In an apparatus for regulating the operation of a steam boiler of the drumless forced flow type having a vaporizer and a superheater, the combination comprising a separator between the vaporizer and the superheater for the water contained in the steam, a single drive motor for all of the feeding mechanisms to the boiler, a conduit for deflecting a part of the combustion gases towards the superheater before they have travelled along the full l ngth of said vaporizer, a first control device automatically operable in accordance with boiler pressure variations, 2, second control device automatically operable in response to the water level variations in the separator, means for discharging from said separator the separated water at a rate which corresponds substantially to the amount of liquid water it is desired for the saturated steam to contain at the inlet of the separator, means operable from the first or said control devices for governing the operation of said motor, the primary regulation of water feed and the primary regulation of the gases of combustion to said superheater, means operable from the other control device for governing the second regulation of water feed without disturbing the speed of said motor, and means for govemirr a second adjustment in the combustion gases directly supplied to the superheater in accordance with the temperature of the superheated steam to maintain that temperature substantially constant.

16. A process for regulating the operation and feedings of a steam generator having a vaporizer, a superheater and an economizer, which com.-

prises dividing the combustion gases flowing through the vaporizer into three currents, passing by normal how one of said currents successively along and over the full heating surface of the vaporizer, along and over the full heating sur face or" the superheater and along and over the full heating surface of the economizer, by-passing the second current in said vaporizer from normal flow through said vaporizer directly to the entrance of the superheater before an excess of heat has been absorbed by the vaporizer, even under conditions of minimum load, by-passing the third current in said vaporizer from normal flow through said vaporizer directly to the entrance of said economizer, controlling the rate of flow of the second current in accordance with the variations of temperature of the superheated steam to maintain that temperature constant, and controlling the rate of flow of the third current in accordance with the variation in the temperature of the water feed at the outlet of the econoniiaer to maintain that temperature constant.

1'7. A process for regulating the operation of a steam generator as described in claim 16, in which a single motor is provided for driving all the feeding mechanisms of the generator, including the water feed mechanism and the mechanism for feeding the elements of combustion, comprising providing a control automatically operable in accordance with the steam pressure variations, providing a second control automatically operable in response to variations of the excess of the water feedings, applying the first of said controls to govern said motor, establishing an automatic regulation in the rates of flow of said second and third currents towards the entrance of the superheater and the entrance of the economizer respectively in accordance with the heat absorption which each of the units comprising the vaporizer, superheater and economizer can theoretically effect within. conditions of load corresponding to the actual velocity of the motor, establishing automatically 2, regulation responsive to the variations of the velocity of the motor to obtain respective proportions between water feed and the feed of the elements of combustion corresponding to the theoretical efiiciency of the generator at the moment, and ap' plying a regulation governed by said second control to adapt the proportion of the volume of feed water in relation to the volumes of the elements of combustion to the actual efiiciency of the generator.

18. A process as described in claim 15 for regulating the operation of a steam generator of the drumless forced flow type having a vaporizer, a superheater and a separator between the vaporizer and the superheater for the water contained in the steam, the excesses of the water feeding being indicated by the water level variations in said separator, said generator having a single motor for driving all the feeding mechanisms of the generator, including the water feed mechanism and the mechanism for feeding the elements of combustion, which process comprises providing a control automatically operable in accordance with the steam pressure variations, providing a second control automatically operable in response to variations in the excess of the water feedings, applying the first of said controls to govern said motor, establishing automatic regulation in the rates of flow of said second and third currents towards the entrance of the superheater and the entrance of the economizer respectively in accordance with the heat absorption which each or the units comprising the-'vapor izer, superheater and economizer can theoretically effect within conditions or load corresponding to the actual velocity of the motor, establishing automatically a regulation responsive to the variations of the velocity of the motor to obtain respective proportions between water feed and the feed of the elements of combustion corresponding to the theoretical efficiency. or the generator at governed by said second control operating to adapt to the variable efficiency or the generator the proportion of the volume or feed water in relation to the volumes of the elements or com" bustion, and continuously discharging from the separator a part or its water at a rate propor tional to the water feeding and at a rate col-re spending substantially to the amount of liquid water it is desired for the saturated steamto contain at its inlet to t? to separator. v

19. A. process for regulating the operation or" a steam generator as described in claim 16, in which a single motor is provided for driving all the feeding mechanisms of the generator, in cluding the water feed mechanism and the mechanism for feeding the elements of combustion, which process comprises providing a control automatically operable in accordance with the steam pressure variations, providing a second control automatically operable in response of the excess of the water feedings, applying the first of said controls to govern said motor, establishing an automatic regulation in. the rates of r'low of said second and third currents towards the entrance of the superheater and the entrance of the economizer respectively in accordance with the heat absorption which each. of the units comprising the vaporizer, super-heater andeconon1../..er can theoretically effect within conditions of load corresponding to the actual velocity of the motor, :1

establishing automatically a regulation responsive to: the variations of the velocity or the'motor to obtain respective. proportions between water feed and the feed 01": the elements of combustion ccrresponding to the theoretical efliciency of the generator at the moment, and appl ing a regulation governed by said second control operating to adapt to the variable efficiency of the generator the proportion of the volume or feed water in relation to the volumes. or the elements of combustle-n, said controls being operated when the steam pressure and the excess of the water feedings depart from normal value, and are arrested immediately after said steam pressure and excess of water feedings cease to depart from said normal value.

20. A process as described in claim 16 for regulating the operation of a steam generator of the drumless forced flow type having a separator between the vaporizer and the superheater for the water contained in the steam, in which process the original feed of the water, fuel and combustion air is supplied through the operati nof a single drive motor controlled by the steam pressure of the generator to maintain said pressure constant, and is supplied at original rates proportioned to satisfy the needs of the generator when it operates according to its condition of substantially maximum efficiency, and in which the excess or water feed from the outlet oithe water feed pump is returned to the inlet of said pump before injection into the generator in re sponse to water level variations in the separator to maintain said level constant.

21. A process for regulating the operation of the moment, applying a regulation to variations the feeding mechanisms to a steam generator having a'vaporizer and super heater. as; described in. claim 16, comprising the steps of directing the icy-passing combustion gases diverted from the main stream over a section of the superheater' and mixing the latter gases in said superheater section with a portion of said first current of normal flow which has been normally discharged from the outlet of the vaporizer, while the remaining portion of said first current is directed over another section or superheater.

22. A process for regulating the operation of a steam generator having a vaporizer, a superheater andan economizer as described in claim it, whichthe gases discharged from the outlet end or the vaporizer are divided into a plurality of 'streamsiin the superheater, and the current by=passed into said superheater is mixed with one of the streams in said superheater before discharge. from said snperheater, and in which the gases discharged from the outlet end or the superheater are divided into a plurality of streams in the economizer and the current by-passed into said economizer is mixed with one of the streams in said economizer before discharge from said economizer.

23. A process for regulating the operation and feedings of a generator vaporizer, a superheater and a single drive motor for all of generator, comprising diverting to said superheater a portion of the main stream of combustion gases normally flowing alone a portion of the heating surface of l vaporizer, and thereby causing the diverted bustion gases to icy-pass 3e rest of the ing surface of said vaporizer, establishing autotactically a first regulation responsive to the variations in the velocity of the motor driving all of the feeding mechanisms, to control the amount of combustion. gases diverted to said superheater, and establishing a scoop.

of said amount in response to the variations of the temperature of the superheated steam to maintain that temperature constant.

24,. A process for regulating the operation of a steam generator having a vaporizer unit, a superhcater unit and an economizer unit as described in claim 16, in which any one of said second andthird by-pasisng currents runs over a portion of one of the units, and before it reaches the outlet of the latter unit it is mixed with the combustion gases normally flowing from the next previous unit, whereby the rest of the unit into which a current is bypassed is heated by the combined action. of the lay-passing current the normal current, and also in which the portions of the superheater unit and the economize unit heated by the Ly-paesing current of the combustion gases are variable and regulated by the corresponding control.

25. A. process for. regulating the operation of a steamboiler of the. druinless forced flow type. descriheclin claim 1, in which an econonrizer is provided-in said boiler, and in which a portion r of the combustion gases normally flowing to wards said supe-rheater and said econoinizer through the vaporizer are deflected from the flow stream to by-pass an outlet section of said vaporizer and to direct the deflected portion of the gases to: said economizer and to said. superheater, while the temperature of the de-. flected gases has not been sensibly reduced to the temperature of the normal combustion gases at said outlet vaporizer section.

26. An apparatus for regulating the feeds of a 

